ABSTRACT
Aim: To investigate the benefit of chemotherapy among early-stage breast cancer patients with 21-gene recurrence scores of 26-30. Methods: We identified 3754 patients in the Surveillance, Epidemiology, and End Results database. Results: 57.6% of the patients received adjuvant chemotherapy. Patients with higher tumor grade, larger tumors and younger age were more likely to receive chemotherapy. The receipt of chemotherapy was independently associated with better breast cancer-specific survival than in patients without chemotherapy before (p = 0.016) and after (p = 0.043) propensity score matching. The sensitivity analyses showed that survival gain was pronounced in patients with poorly differentiated or undifferentiated disease. Conclusions: Adjuvant chemotherapy improves the outcome for early-stage breast cancer with 21-gene recurrence score of 26-30, especially for patients with high-grade tumors.
Lay abstract In current clinical practice, the 21-gene recurrence score has been developed for chemotherapy decision-making based on prognostic risk stratification, especially for patients with tumor size ≤5 cm, node-negative, hormone receptor-positive and HER2-negative breast cancer. However, the chemotherapy benefit in breast cancer patients with a 21-gene recurrence score (RS) of 2630 is unclear. This study aimed to investigate the survival benefit of additional chemotherapy for early-stage breast cancer patients with RS 2630 using the Surveillance, Epidemiology, and End Results data. Our study suggests that the RS 2630 group is regarded as a uniform entity by clinicians. Adjuvant chemotherapy improves the outcome for early-stage breast cancer patients with RS 2630, especially for patients with high-grade tumors.
